This invention relates to trash and waste material reducing apparatus, and is particularly directed to improvements in the effective handling and reduction of such materials in a hammer mill.
Material reducing apparatus which has preceded the present apparatus has embodied the use of air for moving the material as in Williams U.S. Pat. No. 3,702,682 of Nov. 14, 1972, or has embodied reversible hammer rotors and control over the position of breaker plates as in Williams U.S. Pat. No. 3,667,694 of June 6, 1972. Other prior art includes Leggett U.S. Pat. No. 1,751,009 of Mar. 18, 1930; Hartshorn U.S. Pat. No. 2,287,799 of June 30, 1942; Gondard U.S. Pat. No. 3,082,963 of Mar. 26, 1963; and Meyer U.S. Pat. No. 3,442,458 of May 6, 1969. However, the present mixing and segregation of the various fractions of trash and waste material by a controlled air stream and vacuum agitation is new and unique over the foregoing examples of the prior art.
The general objects of the present invention are to combine in a unique way a hammer mill in a housing with a more efficient and positive manner of mixing and segregating waste material and trash in an air stream, and to provide means in the housing for subjecting the trash and waste to a controllable air stream which breaks up clustered material and allows the heavy material to fall out and not get trapped in a recirculating orbit, or return to the hammer mill more than a minimum number of times.
A more specific object of the present invention is to provide a controllable high velocity air stream past the delivery end of material feeding means, and provide a negative pressure gradient or partial vacuum area adjacent the delivery end of the feeding means for effecting a thorough mixing and jet action.
A further object of the present invention is to provide a material reducing mill of reversible character in combination with the structure and means pointed out above and to be described below, all of which provides improved results.